Acute administration of alcohol and marijuana have been shown to profoundly impair memory and cognition and little is known about the nature of these deficits, and the mechanisms underlying them. The observation that cognitively-demanding tasks are particularly disrupted suggests that one way of understanding the effects of alcohol and marijuana is to investigate the types of cognitive strategies utilized when an individual is intoxicated. The present study examines the effects of alcohol and marijuana on cognitive and memory tasks. Specific tests were selected so as to enable a better understanding of the cognitive strategies employed, with several of the tests being modified versions of neuropsychological tests commonly used to clinically determine brain dysfunction. It is anticipated that investigating the cognitive strategies used to solve tests which measure clinical brain dysfunction will enable a better understanding of the detrimental effects of alcohol and intoxication on cognition. Twenty-four male volunteers have been tested and the data are being analyzed.